Transmission line



May 16, 1939. R. w. GEORGE N TRANSMISSION LINE Filed June 20, 1935 Patented May 16, 1939 IPATENT OFFICE TRANSMISSION LINE Ralph W. George, Riverhead, N. Y., aslignor to Radio Corporation oi' America, a corporation of Delaware Application June 20, 1935, Serial No. 27,478

7 Claims. (Cl. 174-117) This invention relates to an improved transmission line, particularly adapted for use in ultra high-frequency circuits.

An object of this invention is to simplify and improve transmission lines which are assembled and ready for use in ultra high-frequency circuits.

Another object of this invention is to provide a two-wire transmission line which will be an improvement over the conventional rubber covered twisted pair lines.

In transmission lines which are to be used at ultra high frequencies the present form of conventional insulated conductors now available have been found to be too high in losses to be useful in ultra high-frequency circuits. Therefore, I propose to improve the present conventional form of conductor by arranging two parallel wires to be embedded in a strip of high-grade insulating material.

This invention will be more completely understood by referring to the various modifications as shown in the accompanying drawing, in which Fig. 1 is an embodiment showing a simple form of composite insulation for retaining two conductors;

Fig. la is a section of Fig. l;

Fig. 2 is a modication similar to that of Fig. 1; and

80 Fig. 2a is a section of Fig. 2;

Isig. 3 is another modification similar to those of Figs. 1 and 2.

In the embodiments shown by Figs. 1, 2, and 3, the transmission line is arranged in a ladder-like construction which is composed of a composite dielectric for spacing two parallel wires I and 2, mechanically apart by rigid insulating elements such as "Isolantite rods 4, molded pheno-condensation products, or the like. These insulating rods 4 are mechanically secured to conductors I and 2 by means of any dielectric material 5 which is capable of molding around the conductors I and 2, for example, rubber, a suitable anchorage means 6 is provided for securing the conductors I and 2 in mechanical engagement with the insulating rods 4.

'I'he modifications shown in Figs. 2 and 3 are similar to that of Fig. 1, except the anchorage means is slightly dierent for assembling and retaining the wires.

While it is desirable that the conductors I and 2 be of solid wire as the current travels on the outer surface at lthe ultra high frequencies, stranded wire will maken more flexible transmis- MisionV line for use V-on slightly lower frequencies.

This improved transmission line may be transposed by twisting and, obviously, the wire size and spacing may be chosen to obtain the desired impedance.

Although only a few modiiications of this in- 5 ventlon have been disclosed, it is to be distinctly understood that other modiiications will suggest themselves to those skilled in the art. Therefore, this invention is not to be limited except as to such limitations as are clearly imposed by the ap- 10 pended claims.

Having thus described claim is:

1. A transmission line for use in ultra highfrequency circuits comprising a pair of parallel u arrangedl conductorsspaced by insulating rods having enlarged ends serving. as anchorage means, said rods and said conductors being mechanically secured to said conductors by a continuous length of insulating binding material 20 surrounding said enlarged ends.

2. A transmission line for use in ultra highfrequency circuits comprising a pair of parallel arranged flexible conductors spaced by insulating rods, said rods and said conductors being me- 25 chanically secured together by a continuous length of flexible insulating material.

3. A transmission line for use in uitra highfrequency circuits comprising a pair of parallel arranged conductors spaced by insulating rods 30 having enlarged ends serving as anchcrage means, said rods and said conductors being mechanically secured together by continuous strips oi.' insulating material.

4. A transmission line for use in ultra high- 35 frequency circuits comprising a pair of parallel arranged conductors spaced oy insulating rods, said rods having enlarged endsand an increased cross-sectional area substantially at the central point between said conductors, said rods being 40 mechanically secured to said conductors by continuous strips of insulating binding material.

5. A transmissidn line for use in ultra highfrequency circuits comprising a. pair of parallel arranged conductors spaced by insulating rods 45 having end slots located in opposition to each other for retaining said conductor, said rods bel ing mechanically secured to said conductors by continuous strips of insulating binding material.

6. A high frequency transmission line compris- 5'0 ing at least two conductors spaced apart from each other by a plurality of insulating rods having enlarged ends, said rods located at right angles to the longitudinal plane of said conductors, said rods being mechanically secured to said my invention, what l conductors by continunus strips of insulating angles to said conductors and spaced apart at binding material. equal intervals. said ros being mechanically 7. A high frequency tron line comsecured to said conductors by continuous strips prising at least two conductors spaced apart from of insulating binding material. 5 each other by a plurality 'of insulating rods having enlarged ends, said rods lacated at right RALPH W. GEORGE. 

